1. Field of the Invention
The present invention relates to an image processing apparatus that process a captured image or the like and, more specifically, to an image processing apparatus and a program product therefore that correct digital images including image data having a special color.
2. Description of the Related Art
In recent years, work of capturing a digital image taken by a digital camera (digital still camera: DSC) or read by a scanner and displaying it on a display device or printing it with a printer has come to be performed widely. Also, work of putting, into a database, digital image data taken by different digital cameras under different conditions (different light sources, locations, times, etc.) and then outputting (visualizing) an edited layout image where images are arranged at prescribed regions has come to be performed commonly. Such kinds of work are performed in a wide variety of scenes such as fields such as the printing market of using images for product handbills, advertisements, magazine articles, etc., the business market of producing exhibition and seminar materials, photographs for recording actual sites, snapshots of merchandise such as real estate properties and products, and like things, and the personal markets in which general users use images personally.
A digital image taken by a digital camera or the like may contain an object having a special color (spot color) such as a corporate color that is used for a corporate logo or the like or a main color of a commodity. In film packages, for example, there may occur a case that a corporate color and a package color are the same. On the other hand, as a future trend of color printers, a technique for forming, in a full-color printer, an image using a colorant of a particular color that cannot be expressed or hard to express by the four colors (yellow, magenta, cyan, and black) that are used ordinarily in full-color printers is now being studied.
Among background art techniques disclosed as patent publications is a technique that is used in image processing for binarizing a color image such as a business document having a relatively small number of colors. Limited colors are detected from color image signals and converted into color codes, and the color image signals are subjected to a bit map conversion. And input color image data are reproduced by limited colors (see JP-A-9-065157 on page 5 and FIG. 3). Another technique relates to spot color processing in a printer. A color patch is scanned by a scanner, and then printing on a 5 printing medium is performed by automatically using the scanned color and similar colors within a certain range around the scanned color (see JP-A-2003-134349 see pages 4 and 5, and FIG. 1).